Biodegradable connectors

ABSTRACT

An expandable bifurcated stent is formed of a main body and a first branch. The body wall is made up of interconnected stent members that define a plurality of cells, at least one of which is a side opening. The first branch body extends from the body wall from at least two regions adjacent the side opening. At least one stent member adjacent the perimeter is bioabsorbable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/773,991, filed on Jul. 6, 2007.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable

BACKGROUND OF THE INVENTION

Stents and similar devices such as stent, stent-grafts, expandableframeworks, and similar implantable medical devices, are radiallyexpandable endoprostheses which are typically intravascular implantscapable of being implanted transluminally and enlarged radially afterbeing introduced percutaneously. Stents may be implanted in a variety ofbody lumens or vessels such as within the vascular system, urinarytracts, bile ducts, fallopian tubes, coronary vessels, secondaryvessels, etc. They may be self-expanding, expanded by an internal radialforce, such as when mounted on a balloon, or a combination ofself-expanding and balloon expandable (hybrid expandable).

Stents may be created by methods including cutting or etching a designfrom a tubular stock, from a flat sheet which is cut or etched and whichis subsequently rolled or from one or more interwoven wires or braids.

Within the vasculature it is not uncommon for stenoses to form at avessel bifurcation. A bifurcation is an area of the vasculature or otherportion of the body where a first (or parent) vessel is bifurcated intotwo or more branch vessels. Where a stenotic lesion or lesions form atsuch a bifurcation, the lesion(s) can affect only one of the vessels(i.e., either of the branch vessels or the parent vessel) two of thevessels, or all three vessels.

The art referred to and/or described above is not intended to constitutean admission that any patent, publication or other information referredto herein is “prior art” with respect to this invention. In addition,this section should not be construed to mean that a search has been madeor that no other pertinent information as defined in 37 C.F.R. §1.56(a)exists.

All U.S. patents and applications and all other published documentsmentioned anywhere in this application are incorporated herein byreference in their entirety.

Without limiting the scope of the invention a brief summary of some ofthe claimed embodiments of the invention is set forth below. Additionaldetails of the summarized embodiments of the invention and/or additionalembodiments of the invention may be found in the Detailed Description ofthe Invention below.

A brief abstract of the technical disclosure in the specification isprovided as well only for the purposes of complying with 37 C.F.R. 1.72.The abstract is not intended to be used for interpreting the scope ofthe claims.

BRIEF SUMMARY

Embodiments of the invention are directed to a bifurcated stent havingan unexpanded state and an expanded state. The stent comprises a mainbody with a body wall. The body wall extends along a main longitudinalaxis from a proximal end to a distal end and defines a lumen between thetwo ends. The body wall is comprised of interconnected stent members, aplurality of which defines a plurality of cells. At least one of thecells is a side opening having a perimeter. The side opening is shapeddifferently then the other cells of the stent.

The stent also comprises a first branch having a first branch body. Thefirst branch body is positioned between the distal end and the proximalend of the main body and extends along a first branch longitudinal axiswhen the stent is in the expanded state. Furthermore, the first branchbody extends from the body wall from at least a first region adjacentthe side opening and a second region adjacent the side opening. At leastone of the stent members adjacent the perimeter is bioabsorbable.

In some embodiments, the stent includes deflectable members which extendfrom the main body at positions about the perimeter of the side opening.

In at least one embodiment, the side opening perimeter includes abioabsorbable expansion joint.

In at least one embodiment, the body wall comprises a plurality ofcircumferential rings, longitudinally offset from one another about themain longitudinal axis. The first branch body also comprises at leastone branch ring being arranged about the first branch axis and extendingfrom the perimeter of the side opening by at least one bioabsorbablestent member.

These and other embodiments which characterize the invention are pointedout with particularity in the claims annexed hereto and forming a parthereof. However, for further understanding of the invention, itsadvantages and objectives obtained by its use, reference should be madeto the drawings which form a further part hereof and the accompanyingdescriptive matter, in which there is illustrated and describedembodiments of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

A detailed description of the invention is hereafter described withspecific reference being made to the drawings.

FIG. 1 a is a side view of an embodiment of the present bifurcatedstent.

FIG. 1 b is a cross-sectional view of the embodiment depicted in FIG. 1a.

FIG. 2 a is a perspective view of an embodiment of the inventive stent,with the deflectable members connected by bioabsorbable stent members.

FIG. 2 b is a perspective view of the embodiment shown in FIG. 2 a,after the bioabsorbable stent members have degraded.

FIG. 3 a is a flat layout of an embodiment of the inventive stent, withbioabsorbable expansion joints.

FIG. 3 b is a flat layout of the embodiment depicted in FIG. 3 a, afterthe bioabsorbable expansion joint has degraded.

FIG. 4 a is a side view of an embodiment of the inventive stent, withcircumferential rings in the main body and branch rings in the branchbody.

FIG. 4 b is a side view of the embodiment depicted in FIG. 4 a, afterthe bioabsorbable stent members have degraded.

FIG. 4 c is a side view of the embodiment depicted in FIG. 4 a, afterthe bioabsorbable stent members have degraded.

FIG. 4 d is a side view of the embodiment depicted in FIG. 4 a, afterthe bioabsorbable stent members have degraded.

FIG. 5 a is a perspective view of an embodiment of the inventive stent,with the deflectable members extending from a bioabsorbable perimeter.

FIG. 5 b is a perspective view of the embodiment shown in FIG. 5 a,after the bioabsorbable perimeter has degraded.

FIG. 6 a is a flat layout of an embodiment of the inventive stent, withcircumferential rings adjacent the side opening engaged to the sideopening by bioabsorbable stent members.

FIG. 6 b is a flat layout of the embodiment depicted in FIG. 6 a withdeflectable members.

FIG. 7 a is a flat layout of an embodiment of the inventive stent, witha bioabsorbable stent member substantially covering the side opening.

FIG. 7 b is a flat layout of an embodiment of the inventive stent, witha plurality of bioabsorbable stent members substantially covering theside opening.

FIG. 8 a is a side view of an embodiment of the inventive stent, withtwo branches extending from the distal end of the main body bybioabsorbable stent members.

FIG. 8 b is a side view of the embodiment depicted in FIG. 8 a, afterthe bioabsorbable stent members have degraded.

FIG. 9 is a flat layout of an embodiment of the inventive stent, with abioabsorbable perimeter.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there aredescribed in detail herein specific preferred embodiments of theinvention. This description is an exemplification of the principles ofthe invention and is not intended to limit the invention to theparticular embodiments illustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated.

FIG. 1 a depicts an embodiment of the invention, which includes abifurcated stent with bioabsorbable members, wherein the stent 12 isshown in an expanded state.

In embodiments of the invention bioabsorbable members are constructedfrom one or more metals, polymers or combinations thereof that arecorrodible so as to dissolve, dissociate or otherwise break down in thebody without ill effect. Examples of such materials have been referredto as being degradable, biodegradable, biologically degradable,erodable, bioabsorbable, bioresorbable, and the like, and are hereincollectively referred to as being bioabsorbable materials.

Examples of bioabsorbable materials include, but are not limited to,poly(hydroxyvalerate), poly(L-lactic acid), polycaprolactone,poly(lactide-co-glycolide), poly(hydroxybutyrate),poly(hydroxybutyrate-co-valerate), polydioxanone, polyorthoesters,polyanhydrides, poly(glycolic acid), poly(D,L-lactic acid),poly(glycolic acid-co-trimethylene carbonate), polyphosphoesters,polyphosphoester urethanes, poly(amino acids), cyanoacrylates,poly(trimethylene carbonate), poly(iminocarbonate), copoly(ether-esters)(e.g. PEO/PLA), polyalkylene oxalates, polyphosphazenes and biomoleculessuch as fibrin, fibrinogen, cellulose, starch, collagen, hyaluronicacid, etc., and mixtures thereof. Further examples of bioabsorbablematerials may be found in U.S. Pat. Nos. 6,258,117, 6,409,754, and7,022,132 and in U.S. Patent Application Publication No. 2002/0107560,the entire contents of which are incorporated herein by reference.

As stated above, the stent comprises a main body 15 and a first branch20. The main body 15 comprises a body wall 25 made up of interconnectedstent members 30. As seen in FIG. 1 a, the body wall 25 extends along amain longitudinal axis 35 from a proximal end 40 of the main body to adistal end 45 of the main body, defining a lumen 50 therethrough.

Regarding the interconnected stent members 30, the stent members 30include struts, connectors, sutures, expansion joints, combinationsthereof, or any number of other structures suitable for use inconstructing a stent. A plurality of the interconnected stent members 30define a plurality of cells 55. At least one of the cells 55 is a sideopening 60. The side opening 60 is distinguishable because it is shapeddifferently then the other cells of the stent. In some embodiments, theside opening 60 is larger than the other cells. Additionally, the sideopening 60 has a perimeter 65. One of ordinary skill in the art willrecognize that the perimeter 65 can be any number of shapes and is notlimited to circular, elliptical, or any of the shapes specificallydepicted in the drawings.

In addition to the main body, the stent further comprises a first branch20 with a first branch body 75, as depicted in the embodiment shown inFIG. 1 a. The first branch body 75 is positioned between the proximalend 40 and the distal end 45 of the main body 15. The first branch body75 extends along a first branch longitudinal axis 80 when the stent isin the expanded state. As seen in FIG. 1 a, the first branch body 75extends from the body wall 25 from at least a first region 85 adjacentthe side opening 60 and a second region 90 adjacent the side opening 60.At least one stent member adjacent the perimeter 65 is bioabsorbable.One or more bioabsorbable stent member(s) 70 is/are positioned anywhereon or within the structure of the stent 12. An example of embodimentsincluding at least one bioabsorbable stent member 70, and the positionof the member are shown in both FIG. 1 a and in cross-sectional viewFIG. 1 b. The bioabsorbable stent member could be within the main bodyor within the first branch body.

The use of bioabsorbable stent members near or at the side opening isbeneficial because it increases the stent's resistance to fatigue. Whenstents are juxtaposed or extended across a bifurcation in a vessel, forexample, the juxtaposition or extension may stress areas of the stent.By placing bioabsorbable material at one or more of these high-stressareas, the bioabsorbable material will be gradually absorbed into thebody, eliminating the stress. As a consequence of the absorption, theinventive stent will separate from itself, leaving in some embodimentsthe main body and the first branch body. Thus, the main vessel and thebranch vessel will be kept open by the remaining portions of the stent.One skilled in the art will recognize that by selecting differentbioabsorbable materials or varying the thickness of the bioabsorbablematerials, the time it takes for the material to bioabsorb can becontrolled. Thus in accordance with the present invention a bifurcatedstent is provided wherein bioabsorbtion of a desired region or regionsof the stent is made to occur immediately or soon after deployment, inseveral months, in several years, or at different rates for differentregions of the stent. In some embodiments of the present invention, thefirst branch body comprises a plurality of deflectable members 95, asillustrated in side-view FIGS. 2 a and 2 b. These deflectable members 95may define undulating petals, similar to those shown and described inU.S. Patent Application Publication Nos. 2004/0138737 and 2005/0102023,the entire contents of each being incorporated herein by reference. Eachof the deflectable members 95 has a first end 100 and a second end 105.As shown in FIG. 2 a, the first end 100 of each deflectable member 95extends from the main body 15 at positions about the perimeter 65 of theside opening. In the expanded state, depicted in FIG. 2 b, thedeflectable members 95 extend into the branch vessel. One of ordinaryskill in the art will recognize that there are a number of ways in whichthe deflectable members 95 may be deflected, including inserting anexpandable balloon through the main body of the stent and through theside opening (not depicted). FIG. 2 a shows the second ends 105 ofadjacent deflectable members 95 being connected by at least onebioabsorbable stent member 70. In some embodiments it may be desirableto have the bioabsorbable connectors degrade upon stent deployment, suchas depicted in FIG. 2 b, which shows the deflectable members 95 afterthe bioabsorbable stent members have degraded.

In FIG. 3 a, the embodiment of the stent depicted in FIG. 2 a furtherincludes a bioabsorbable expansion joint 110. Specifically, theperimeter 65 of the side opening 60 includes the bioabsorbable expansionjoint 110. Including at least one bioabsorbable expansion joint allowsthe side opening to expand over time, reducing the stress on theperimeter. FIG. 3 b depicts the stent of FIG. 3 a after thebioabsorbable expansion joint 110 has degraded. This degradationeliminates the stress on the perimeter by allowing the perimeter toexpand.

Referring now to FIG. 4 a, in the embodiment shown, the body wall 25comprises a plurality of circumferential rings 115 longitudinally offsetfrom one another about the main longitudinal axis 35. In FIG. 4 a, thefirst branch body 75 shown comprises at least one branch ring 120arranged about the first branch axis 80. The branch ring 120 extendsfrom the perimeter 65 of the side opening by at least one bioabsorbablestent member 70. After the bioabsorbable stent members degrade, thebranch body 75 separates from the perimeter 65, as illustrated in FIG. 4b.

In the embodiment depicted in FIG. 4 a, adjacent circumferential rings115 are also connected to one another by bioabsorbable stent members 70.As illustrated in FIG. 4 c, this allows at least a portion of the mainbody 25 to separate.

In some embodiments, as also depicted in FIG. 4 a, the stent comprises aplurality of branch rings 120. Adjacent branch rings 120 are connectedto one another by at least one bioabsorbable stent member 70. Asillustrated in FIG. 4 d, this allows at least a portion of the branchbody 75 to separate, leaving multiple branch rings after thebioabsorbable stent member(s) degrade.

In the embodiment depicted in FIG. 5 a, the perimeter 65 is made up ofat least one bioabsorbable stent member 70. The stent further comprisesa plurality of deflectable members 95, each having a first end 100 and asecond end 105. Provision of the bioabsorbable perimeter mitigatesfracturing between the main body and the deflectable members. The firstend 100 of each deflectable member 95 extends from the main body 15 atpositions about the perimeter 65 of the side opening. In the expandedstate, as shown in FIG. 5 a, the deflectable members 95 extend into avessel branch. FIG. 5 b depicts the stent 12 of FIG. 5 a after thebioabsorbable stent member(s) 70 of the perimeter has degraded. As seenin FIG. 5 b, the deflectable members 95 are separated from the main body15 after the perimeter 65 has degraded.

In some embodiments, as depicted in FIG. 6 a, the body wall 25 comprisesa plurality of circumferential rings 115 a being longitudinally offsetfrom one another about the main longitudinal axis 35. As illustrated, atleast two adjacent circumferential rings 115 a are connected to oneanother by at least one bioabsorbable stent member 70. Also, at leastone of the circumferential rings 115 a adjacent the perimeter 65 isconnected to the perimeter 65 by at least one bioabsorbable stent member70. In some embodiments, the stent includes deflectable members 95, likein FIG. 6 b.

In at least one embodiment, as shown in FIG. 6 a, the stent furthercomprises at least one circumferential ring 115 b engaged to theperimeter 65. One of the circumferential rings 115 a adjacent andconnected to the perimeter 65 by at least one bioabsorbable stent member70 is also connected by at least one bioabsorbable stent member 70 to acircumferential ring 115 b engaged to the perimeter 65. The stentfurther comprises a plurality of deflectable members 95 having a firstend 100 and a second end 105, as shown in FIG. 6 b. The first end 100 ofeach deflectable member 95 extends from the main body at positions aboutthe perimeter 65.

Referring now to FIG. 7 a, in at least one embodiment, at least onebioabsorbable stent member 70 substantially covers the side opening 60.As seen in FIG. 7 a, the covering extends from the perimeter 65. In someembodiments, the covering is engaged to the perimeter by otherbioabsorbable stent members 70, as in FIG. 7 a. In another embodiment,the covering extends directly from the perimeter 65. In someembodiments, as shown in FIG. 7 b, a plurality of bioabsorbable stentmembers 70 substantially covers the side opening 60. Although depictedas concentric circles, it should be noted that the bioabsorbable stentmembers 70 could be arranged in any number of designs to cover the sideopening 60.

It should be noted that in the unexpanded state, the first branch body75 would lie flat on the main body 15. The first branch body 75 could beexpanded into a second lumen with a secondary balloon attached to themain balloon, a POBA balloon pushed through the center of the firstbranch body 75 and expanded, or a secondary deployment object such as aconic-shaped feature at the end of a catheter could be extended throughfirst branch body 75 to push it open.

Referring now to the embodiment depicted in FIG. 7 b, the first branchbody 75, shown with ring-like stent members 70, could be expanded into asecond lumen by a ratcheting procedure. One of ordinary skill in the artwill recognize that there are a number of ways in which the ratchetingcan be performed. One ratcheting method would be similar to that of zipties, which allows the rings to open, but prevents the ring fromclosing. In some embodiments, the ring-like stent members 70 haveelastic properties that allow them to stretch open, at which point thering-like stent members 70 either separate as they expand, or dependingon the taper of the second lumen, the ring-like stent members 70 arepushed into the second lumen, resulting in a conical shape.

In the embodiment depicted in FIG. 8 a, a Y-stent is depicted. The stent12 in FIG. 8 a comprises a main body 15 and two branches (20, 125). Themain body 15 has a body wall 25 which extends along a main longitudinalaxis 35 from a proximal end 40 to a distal end 45 and defines a lumen 50therethrough. The body wall 25 is comprised of interconnected stentmembers 30.

As mentioned above, the bifurcated stent of FIG. 8 a has two branches, afirst branch 20 and a second branch 125. The first branch 20 has a firstbranch body 75 which extends along a first branch longitudinal axis 80when the stent 12 is in the expanded state, as in FIG. 8 a. Like themain body, the first branch body 75 is comprised of interconnected stentmembers 30.

The second branch 125 of stent 12 has a second branch body 130 whichextends along a second branch longitudinal axis 135 when the stent 12 isin the expanded state. The second branch body 130 is also comprised ofinterconnected stent members 30.

As seen in FIG. 8 a, the first and second branch bodies 75, 130 extendfrom the main body 15 at its distal end 45. Furthermore, at least one ofthe stent members 30 of the first branch body 75 and the second branchbody 130 are connected to the main body 15 at the distal end 45 by atleast one bioabsorbable stent member 70.

FIG. 8 b depicts the stent 12 of FIG. 8 a after the bioabsorbable stentmembers 70 have degraded. The first branch 20 and the second branch 125have separated from the main body 15.

It should be noted that the terms “main body”, “first branch”, and“second branch” do not imply that the diameter of the main branch islarger than the diameters of the first or second branches. Although thiscould be true, it is not necessarily so. In some embodiments, thediameter of the first branch D2 or the diameter of the second branch D3is equal to or greater than the main branch diameter D1.

Referring now to FIG. 9, in at least one embodiment the expandable stent12 has a main body 15 with a body wall 25 which extends along a mainlongitudinal axis 35 from a proximal end 40 to a distal end 45 anddefining a lumen 50 therethrough.

As in other embodiments described above, the body wall 25 is comprisedof interconnected stent members 30, a plurality of which define aplurality of cells 55. At least one of the cells 55 is a side opening60. The side opening 60 is distinguishable because it is shapeddifferently then the other cells of the stent. In general, the sideopening 60 is shaped differently than the other cells in that it islarger than the other cells. Additionally, the side opening 60 has aperimeter 65. In the embodiment depicted in FIG. 9, the perimeter 65 isbioabsorbable.

In some embodiments, the stent may include one or more areas, bands,coatings, members, etc. that is (are) detectable by imaging modalitiessuch as X-Ray, MRI, ultrasound, etc. In some embodiments at least aportion of the stent and/or adjacent assembly is at least partiallyradiopaque.

In some embodiments at least a portion of the stent is configured toinclude one or more mechanisms for the delivery of a therapeutic agent.Often the agent will be in the form of a coating or other layer (orlayers) of material placed on a surface region of the stent, which isadapted to be released at the site of the stent's implantation or areasadjacent thereto.

A therapeutic agent may be a drug or other pharmaceutical product suchas non-genetic agents, genetic agents, cellular material, etc. Someexamples of suitable non-genetic therapeutic agents include but are notlimited to: anti-thrombogenic agents such as heparin, heparinderivatives, vascular cell growth promoters, growth factor inhibitors,Paclitaxel, etc. Where an agent includes a genetic therapeutic agent,such a genetic agent may include but is not limited to: DNA, RNA andtheir respective derivatives and/or components; hedgehog proteins, etc.Where a therapeutic agent includes cellular material, the cellularmaterial may include but is not limited to: cells of human origin and/ornon-human origin as well as their respective components and/orderivatives thereof. Where the therapeutic agent includes a polymeragent, the polymer agent may be apolystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS),polyethylene oxide, silicone rubber and/or any other suitable substrate.

The above disclosure is intended to be illustrative and not exhaustive.This description will suggest many variations and alternatives to one ofordinary skill in this art. The various elements shown in the individualfigures and described above may be combined or modified for combinationas desired. All these alternatives and variations are intended to beincluded within the scope of the claims where the term “comprising”means “including, but not limited to”.

Further, the particular features presented in the dependent claims canbe combined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each singly dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below.

This completes the description of the preferred and alternateembodiments of the invention. Those skilled in the art may recognizeother equivalents to the specific embodiment described herein whichequivalents are intended to be encompassed by the claims attachedhereto.

1. A bifurcated stent comprising: a plurality of interconnected stentmembers defining a side branch opening, the side branch opening having aperimeter and a plurality of deflectable members, the deflectablemembers having a first end and a second end, the first end engaged tothe perimeter, the second end extending into the side branch opening,wherein at least two of the plurality of deflectable members areconnected to one another via at least one bioabsorbable stent member. 2.The bifurcated stent of claim 1, wherein the at least one bioabsorbablestent member is curved.
 3. The bifurcated stent of claim 1 furthercomprising a main body portion, an unexpanded configuration, and anexpanded configuration; the main body portion further comprising anouter surface; wherein, in the unexpanded configuration, the deflectablemembers are coplanar with the outer surface of the main body portion,and, in the expanded configuration, the deflectable members extendoutwardly from the outer surface of the main body portion.
 4. Thebifurcated stent of claim 1, wherein each of the deflectable memberscomprises a side branch petal.
 5. The bifurcated stent of claim 1,wherein the at least one bioabsorbable stent member comprises a materialselected from the group consisting of: poly(hydroxyvalerate),poly(L-lactic acid), polycaprolactone, poly(lactide-co-glycolide),poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polydioxanone,polyorthoesters, polyanhydrides, poly(glycolic acid), poly(D,L-lacticacid), poly(glycolic acid-co-trimethylene carbonate), polyphosphoesters,polyphosphoester urethanes, poly(amino acids), cyanoacrylates,poly(trimethylene carbonate), poly(iminocarbonate),copoly(ether-esters), polyalkylene oxalates, polyphosphazenes, fibrin,fibrinogen, cellulose, starch, collagen, hyaluronic acid, andcombinations thereof.
 6. The bifurcated stent of claim 1, wherein the atleast one bioabsorbable stent member extends from the second end of oneof the plurality of deflectable members to the second end of another ofthe plurality of deflectable members.
 7. The bifurcated stent of claim1, wherein at least a portion of the perimeter is bioabsorbable.
 8. Thebifurcated stent of claim 1, wherein the at least one bioabsorbablestent member comprises a plurality of bioabsorbable stent members, theplurality of bioabsorbable stent members being concentric with theperimeter of the branch opening.
 9. A bifurcated stent comprising: anunexpanded configuration and an expanded configuration; a plurality ofinterconnected stent members defining a plurality of cells, at least oneof the plurality of cells comprising a side opening, the side openingbeing shaped differently than the other cells, the side opening having aperimeter; and a plurality of side branch petals extending from theperimeter into the side opening; in an unexpanded configuration, theside branch petals being connected one to another by at least onebioabsorbable stent member.
 10. The bifurcated stent of claim 9,wherein, in an expanded configuration, the at least one bioabsorbablestent member is no longer connecting the side branch petals.
 11. Thebifurcated stent of claim 9, wherein the perimeter of the side openingis circular.
 12. The bifurcated stent of claim 11, wherein the at leastone bioabsorbable stent member is concentric with the perimeter.
 13. Thebifurcated stent of claim 9, wherein at least a portion of the perimeteris bioabsorbable.
 14. The bifurcated stent of claim 13 furthercomprising a main stent body, wherein, in an unexpanded configuration,the side branch petals are connected to the main stent body and, in anexpanded configuration, the side branch petals are disconnected from themain stent body.
 15. The bifurcated stent of claim 14, wherein each ofthe plurality of side branch petals comprises a second end, the at leastone bioabsorbable stent member extending from the second end of one ofthe plurality of side branch petals to the second end of another of theplurality side branch petals.